One of the most intriguing questions about the new computer technology that has appeared over the past few decades is whether we humans will ever be able to make computers learn. As is painfully obvious to even the most casual computer user, most current computers do not. Yet if we could devise learning techniques that enable computers to routinely improve their performance through experience, the impact would be enormous. The result would be an explosion of new computer applications that would suddenly become economically feasible (e. g. , personalized computer assistants that automatically tune themselves to the needs of individual users), and a dramatic improvement in the quality of current computer applications (e. g. , imagine an airline scheduling program that improves its scheduling method based on analyzing past delays). And while the potential economic impact of successful learning methods is sufficient reason to invest in research into machine learning, there is a second significant reason: studying machine learning helps us understand our own human learning abilities and disabilities, leading to the possibility of improved methods in education. While many open questions remain about the methods by which machines and humans might learn, significant progress has been made.

One of the most intriguing questions about the new computer technology that has appeared over the past few decades is whether we humans will ever be able to make computers learn. As is painfully obvious to even the most casual computer user, most current computers do not. Yet if we could devise learning techniques that enable computers to routinely improve their performance through experience, the impact would be enormous. The result would be an explosion of new computer applications that would suddenly become economically feasible (e. g. , personalized computer assistants that automatically tune themselves to the needs of individual users), and a dramatic improvement in the quality of current computer applications (e. g. , imagine an airline scheduling program that improves its scheduling method based on analyzing past delays). And while the potential economic impact ofsuccessful learning methods is sufficient reason to invest in research into machine learning, there is a second significant reason: studying machine learning helps us understand our own human learning abilities and disabilities, leading to the possibility of improved methods in education. While many open questions remain aboutthe methods by which machines and humans might learn, significant progress has been made.

The two volumes of Foundations of Knowledge Acquisition document the recent progress of basic research in knowledge acquisition sponsored by the Office of Naval Research. This volume is subtitled Machine Learning, and there is a companion volume subtitled Cognitive Models of Complex Learning. Funding was provided by a five-year Accelerated Research Initiative (ARI), and made possible significant advances in the scientific understanding of how machines and humans can acquire new knowledge so as to exhibit improved problem-solving behavior. Significant progress in machine learning is reported along a variety of fronts. Chapters in Machine Learning include work in analogical reasoning; induction and discovery; learning and planning; learning by competition, using genetic algorithms; and theoretical limitations. Knowledge acquisition as pursued under the ARI was a coordinated research thrust into both machine learning and human learning. Chapters in Cognitive Modles of Complex Learning, also published by Kluwer Academic Publishers, include summaries of work by cognitive scientists who do computational modeling of human learning.In fact, an accomplishment of research previously sponsored by ONR's Cognitive Science Program was insight into the knowledge and skills that distinguish human novices from human experts in various domains; the Cognitive interest in the ARI was then to characterize how the transition from novice to expert actually takes place. These volumes of Foundations of Knowledge Acquisition serve as excellent reference sources by bringing together descriptions of recent and on-going research at the forefront of progress in one of the most challenging arenas of artificial intelligence and cognitive science. In addition, contributing authors comment on exciting future directions for research.

The two volumes of Foundations of Knowledge Acquisition document the recent progress of basic research in knowledge acquisition sponsored by the Office of Naval Research. This volume is subtitled Cognitive Models of Complex Learning, and there is a companion volume, subtitles Machine Learning. Funding was provided by a five-year Accelerated Research Initiative (ARI), and made possible significant advances in the scientific understanding of how machines and humans can acquire new knowledge so as to exhibit improved problem-solving behavior. Knowledge acquisition, as persued under the ARI, was a coordinated research thrust into both machine learning and the human learning. Chapters in Cognitive Models of Complex Learning thus include summaries of work by cognitive scientists who do computational modeling of human learning. In fact, an accomplishment of research previously sponsored by ONR's Cognitive Science Program gave insight into the knowledge and skills that distinguish human novices from human experts in various domains; the cognitive interest in the ARI was then to characterize how the transition form novice to expert actually takes place.Chapters particularly relevant to that concern are those written by Anderson, Kieras, Marshall, Ohlsson, and VanLehn. Significant progress in machine learning is reported along in a variety of fronts in the companion volume, Machine Learning, also published by Kluwer Academic Publishers. Included is work in analogical reasoning; induction and discovery; explanation-based learning; learning by competition, using genetic algorithms; learning within natural language systems; theoretical limitations, learning in Soar, a proposed general architecture for intelligent systems; and case-based reasoning. These volumes of Foundations of Knowledge Acquisition are excellent reference sources by bringing together descriptions of recent and ongoing research at the forefront of progress in one the most challenging arenas of artificial intelligence and cognitive science. In addition, contributing authors comment on ecxiting future directions for research.